Interview with scholar, translator and lexicographer Donald Rayfield

Donald Rayfield is Emeritus Professor of Russian and Georgian at Queen Mary, University of London. He has been at the forefront of Georgian studies for many years and has published widely on Georgia, authoring several major studies on its literature and history, and translating works by Galaktion Tabidze, Otar Chiladze, Akaki Tsereteli and, most recently, Mikheil Javakhishvili. Slovo meets him to find out about the past, present and (speculative) future of this rich but much underrepresented literature in the Anglophone world

Investigating the relationship between management practices and genetic diversity: a population genetics study of pen shell clam (Atrina tuberculosa) in the Gulf of California, Mexico

The management of commercial fisheries is complicated by the movement of the resource of interest among areas with different management practices. When a species is heavily harvested in one portion of its range, the effects are translated to other fisheries in terms of a decline in abundance, or in some cases, a loss of genetic diversity. Conserving genetic diversity is important, especially in commercially harvested populations, because it provides the population with greater resilience to changing environmental conditions. One popular strategy that fisheries managers use to alleviate the differences in fishing pressures across the entire range of a species is the establishment of marine protected areas. MPAs also act to conserve biodiversity within their boundaries, and many areas of the world’s highest marine biodiversity occur in developing countries where commercial fishing is practiced at small scales. Understanding the interplay between MPAs and small-scale fisheries will allow for the most comprehensive management decisions. My research uses molecular techniques to investigate the levels of genetic diversity between two commercially harvested bivalve populations in the Gulf of California, Mexico in order to evaluate the effectiveness of a community-based MPA in terms of a potential genetic benefit to an open-access fishery. The results show no significant genetic structure or difference in levels of genetic diversity between the two populations, and the lack of private alleles indicates that there is positive gene flow between these two areas by means of larval transport. Despite the influx of larvae from the MPA to the open-access fishery, pen shell abundances continue to decline, and these data suggest that the presence of an MPA adjacent to this open-access fishery is not enough to sustain the population under current harvesting practices

Within-guild dietary discrimination from 3-D textural analysis of tooth microwear in insectivorous mammals

Resource exploitation and competition for food are important selective pressures in animal evolution. A number of recent investigations have focused on linkages between diversification, trophic morphology and diet in bats, partly because their roosting habits mean that for many bat species diet can be quantified relatively easily through faecal analysis. Dietary analysis in mammals is otherwise invasive, complicated, time consuming and expensive. Here we present evidence from insectivorous bats that analysis of three-dimensional (3-D) textures of tooth microwear using International Organization for Standardization (ISO) roughness parameters derived from sub-micron surface data provides an additional, powerful tool for investigation of trophic resource exploitation in mammals. Our approach, like scale-sensitive fractal analysis, offers considerable advantages over twodimensional (2-D) methods of microwear analysis, including improvements in robustness, repeatability and comparability of studies. Our results constitute the first analysis of microwear textures in carnivorous mammals based on ISO roughness parameters. They demonstrate that the method is capable of dietary discrimination, even between cryptic species with subtly different diets within trophic guilds, and even when sample sizes are small. We find significant differences in microwear textures between insectivore species whose diet contains different proportions of ‘hard’ prey (such as beetles) and ‘soft’ prey (such as moths), and multivariate analyses are able to distinguish between species with different diets based solely on their tooth microwear textures. Our results show that, compared with previous 2-D analyses of microwear in bats, ISO roughness parameters provide a much more sophisticated characterization of the nature of microwear surfaces and can yield more robust and subtle dietary discrimination. ISO-based textural analysis of tooth microwear thus has a useful role to play, complementing existing approaches, in trophic analysis of mammals, both extant and extinct

Functional evolution of the feeding system in rodents

The masticatory musculature of rodents has evolved to enable both gnawing at the incisors and chewing at the molars. In particular, the masseter muscle is highly specialised, having extended anteriorly to originate from the rostrum. All living rodents have achieved this masseteric expansion in one of three ways, known as the sciuromorph, hystricomorph and myomorph conditions. Here, we used finite element analysis (FEA) to investigate the biomechanical implications of these three morphologies, in a squirrel, guinea pig and rat. In particular, we wished to determine whether each of the three morphologies is better adapted for either gnawing or chewing. Results show that squirrels are more efficient at muscle-bite force transmission during incisor gnawing than guinea pigs, and that guinea pigs are more efficient at molar chewing than squirrels. This matches the known diet of nuts and seeds that squirrels gnaw, and of grasses that guinea pigs grind down with their molars. Surprisingly, results also indicate that rats are more efficient as well as more versatile feeders than both the squirrel and guinea pig. There seems to be no compromise in biting efficiency to accommodate the wider range of foodstuffs and the more general feeding behaviour adopted by rats. Our results show that the morphology of the skull and masticatory muscles have allowed squirrels to specialise as gnawers and guinea pigs as chewers, but that rats are high-performance generalists, which helps explain their overwhelming success as a group

Adaptive plasticity in the mouse mandible

BACKGROUND: Plasticity, i.e. non-heritable morphological variation, enables organisms to modify the shape of their skeletal tissues in response to varying environmental stimuli. Plastic variation may also allow individuals to survive in the face of new environmental conditions, enabling the evolution of heritable adaptive traits. However, it is uncertain whether such a plastic response of morphology constitutes an evolutionary adaption itself. Here we investigate whether shape differences due to plastic bone remodelling have functionally advantageous biomechanical consequences in mouse mandibles. Shape characteristics of mandibles from two groups of inbred laboratory mice fed either rodent pellets or ground pellets mixed with jelly were assessed using geometric morphometrics and mechanical advantage measurements of jaw adductor musculature. RESULTS: Mandibles raised on diets with differing food consistency showed significant differences in shape, which in turn altered their biomechanical profile. Mice raised on a soft food diet show a reduction in mechanical advantage relative to mice of the same inbred strain raised on a typical hard food diet. Further, the soft food eaters showed lower levels of integration between jaw regions, particularly between the molar and angular region relative to hard food eaters. CONCLUSIONS: Bone remodelling in mouse mandibles allows for significant shifts in biomechanical ability. Food consistency significantly influences this process in an adaptive direction, as mice raised on hard food develop jaws better suited to handle hard foods. This remodelling also affects the organisation of the mandible, as mice raised on soft food appear to be released from developmental constraints showing less overall integration than those raised on hard foods, but with a shift of integration towards the most solicited regions of the mandible facing such a food, namely the incisors. Our results illustrate how environmentally driven plasticity can lead to adaptive functional changes that increase biomechanical efficiency of food processing in the face of an increased solicitation. In contrast, decreased demand in terms of food processing seems to release developmental interactions between jaw parts involved in mastication, and may generate new patterns of co-variation, possibly opening new directions to subsequent selection. Overall, our results emphasize that mandible shape and integration evolved as parts of a complex system including mechanical loading food resource utilization and possibly foraging behaviour

Retrodeformation and muscular reconstruction of ornithomimosaurian dinosaur crania

Ornithomimosaur dinosaurs evolved lightweight, edentulous skulls that possessed keratinous rhamphothecae. Understanding the anatomy of these taxa allows for a greater understanding of “ostrich-mimic” dinosaurs and character change during theropod dinosaur evolution. However, taphonomic processes during fossilisation often distort fossil remains. Retrodeformation offers a means by which to recover a hypothesis of the original anatomy of the specimen, and 3D scanning technologies present a way to constrain and document the retrodeformation process. Using computed tomography (CT) scan data, specimen specific retrodeformations were performed on three-dimensionally preserved but taphonomically distorted skulls of the deinocheirid Garudimimus brevipes Barsbold, 1981 and the ornithomimids Struthiomimus altus Lambe, 1902 and Ornithomimus edmontonicus Sternberg, 1933. This allowed for a reconstruction of the adductor musculature, which was then mapped onto the crania, from which muscle mechanical advantage and bite forces were calculated pre- and post-retrodeformation. The extent of the rhamphotheca was varied in each taxon to represent morphologies found within modern Aves. Well constrained retrodeformation allows for increased confidence in anatomical and functional analysis of fossil specimens and offers an opportunity to more fully understand the soft tissue anatomy of extinct taxa

Validation experiments on finite element models of an ostrich (Struthio camelus) cranium.

The first finite element (FE) validation of a complete avian cranium was performed on an extant palaeognath, the ostrich (Struthio camelus). Ex-vivo strains were collected from the cranial bone and rhamphotheca. These experimental strains were then compared to convergence tested, specimen-specific finite element (FE) models. The FE models contained segmented cortical and trabecular bone, sutures and the keratinous rhamphotheca as identified from micro-CT scan data. Each of these individual materials was assigned isotropic material properties either from the literature or from nanoindentation, and the FE models compared to the ex-vivo results. The FE models generally replicate the location of peak strains and reflect the correct mode of deformation in the rostral region. The models are too stiff in regions of experimentally recorded high strain and too elastic in regions of low experimentally recorded low strain. The mode of deformation in the low strain neurocranial region is not replicated by the FE models, and although the models replicate strain orientations to within 10° in some regions, in most regions the correlation is not strong. Cranial sutures, as has previously been found in other taxa, are important for modifying both strain magnitude and strain patterns across the entire skull, but especially between opposing the sutural junctions. Experimentally, we find that the strains on the surface of the rhamphotheca are much lower than those found on nearby bone. The FE models produce much higher principal strains despite similar strain ratios across the entirety of the rhamphotheca. This study emphasises the importance of attempting to validate FE models, modelling sutures and rhamphothecae in birds, and shows that whilst location of peak strain and patterns of deformation can be modelled, replicating experimental data in digital models of avian crania remains problematic

Association between breastfeeding support and breastfeeding rates in the UK: a comparison of late preterm and term infants.

OBJECTIVE: To explore the association between breastfeeding support and breastfeeding among late preterm (gestation 34-36 weeks) and term (gestation ≥37 weeks) infants. METHODS: Secondary analysis of the UK 2010 Infant Feeding Survey. Logistic regression was used to determine the association of breastfeeding support with breastfeeding at 10 days and 6 weeks in late preterm and term infants. RESULTS: The study included 14,525 term and 579 late preterm infants. A total of 11,729 infants initiated breastfeeding (11,292 (81.1%) term, 437 (79.4%) late preterm infants, p=0.425). Of these, 9230 (84.3%) term and 365 (85.6%) late preterm infants were breastfeeding at 10 days (p=0.586); of these 7547 (82.0%) term and 281 (75.4%) late preterm infants were still breastfeeding at 6 weeks (p=0.012). Mothers who reported receiving contact details for breastfeeding support groups had a higher likelihood of breastfeeding late preterm (adjusted ORs, aOR 3.14, 95% CI 1.40 to 7.04) and term infants (aOR 2.24, 95% CI 1.86 to 2.68) at 10 days and term infants at 6 weeks (aOR 1.83, 95% CI 1.51 to 2.22). Those who reported that they did not receive enough help with breastfeeding in hospital had a lower likelihood of breastfeeding late preterm at 10 days and term infants at 10 days and 6 weeks, compared to those who reported having enough help. CONCLUSIONS: Receiving sufficient help with breastfeeding in hospital and the contact details for breastfeeding support groups is associated with breastfeeding term infants up to 6 weeks and late preterm infants at 10 days

What more can we know about Chekhov?

What more can we know about Chekhov? es — junto a 'Medicine is my legitimate wife, and literature is my mistress"— una de las dos conferencias que pronunció el profesor Donald Rayfield en las VII Lecciones Anuales de Poética de la Cátedra Félix Huarte, celebradas con motivo del centenario de la muerte de Antón Chéjov (1860-1904), los días 21 y 22 de abril de 2004